#include <iostream>


int main() {
    int x = 1;
    int y = 1;
    int *p;
    // std::cin >> *p;
    // p = (int*)std::malloc(sizeof(int));
    scanf("%d", p);
    while(x < *p) {
        x = x + *p;
        y = y + 1;
    }
    return x + y;
}